Many medical interventional procedures are dependent on endoscopes to deliver diagnostic and therapeutic catheters to GI, URO, and biliary locations throughout the body. In these types of procedures, the area for maneuvering the endoscope is limited by the working channel diameter. Further limitations regarding the areas that are accessible to the endoscope are due to the physical constraints caused the size and stiffness of the endoscope. Furthermore, with regard to the comfort of the patient, endoscopic procedures are often very painful and require sedation.
A typical endoscope has an illumination channel and an imaging channel, both of which may be made of a bundle of optical fibers. The illumination channel is coupled to a light source to illuminate an internal body cavity of a patient, and the imaging channel transmits an image created by a lens at the distal end of the endoscope to a connected camera unit or display device. As an alternative to an imaging channel made of a bundle of optical fibers, a semiconductor-type camera can also be attached onto the distal tip. One drawback of this alternative is that such cameras are relatively large in size, in comparison to the dimensions needed for certain surgical procedures. Another issue with either the semiconductor-type camera or the bundle of fibers is that the ability to see a larger area requires moving the camera or the bundle of fibers. This type of movement is relatively complex to implement, and requires even more area. Furthermore, while endoscopes are a proven technology, they are relatively complex and expensive to manufacture.
Certain known systems have attempted to produce high-resolution images with a small diameter catheter, most involving optical fibers or fiber imaging bundles in some way. The cost and complexity of an imaging bundle-based vision catheter severely limits its application in the GI and URO fields. The size and number of individual light carrying fibers that comprise an imaging fiber bundle limit the image resolution. For these and other reasons, endoscopes have moved to imaging arrays at the distal tip of the endoscope, which are cheaper, and produce higher resolution images, while increasing the life span of the scope. Due to the size of the arrays and the processing that must take place near the arrays, the endoscope diameters are generally quite large. In addition, they usually require a light source and working channel to allow the clinician to perform therapeutic procedures.
The present invention is directed to an apparatus that overcomes the foregoing and other disadvantages. More specifically, the present invention is directed to a much smaller profile catheter-based device that provides imaging capabilities that are comparable to those of endoscopes.